Fastening inserting machine



Feb. 1e, 1943.

G. R. coYNE FASTENING. INSERTING MACHINE Filed Deo. 10, 1940 Patented Feb. 16, 1943 FASTENING INSERTIN G MACHINE Guy R. Coyne, Milwaukee, Wis., assignor to United Shoe Machinery Corporation, Flemington, N. J., a corporation of New Jersey Application December 10, 1940, Serial No. 369,454

12 Claims. l(Cl. 1-30) This invention relates to fastening inserting machines and is illustrated herein as embodied in a machine arranged to insert fastenings or pegs of ber material into work pieces such as shoes.

When fastenings or pegs of ber material are inserted into work pieces such, for example, as the sole or bottom portions of shoes, it is often desirable to vary the lengths of the fastenings in accordance with the thickness of the different portions of the shoe bottom into which the fastenings are to be inserted. This gives the ber fastenings maximum holding power and insures that they Will not pull out even in shoes having relatively thin insoles. When the heel seats of Goodyear welt shoes, for example, are nailed or pegged on the last it is impossible to determine the thickness of the shoe bottoms by calipering as might be done if the operation were performed off the last.

It has been found practicable, however, as illustrated in Letters Patent of the United States No. 1,849,253, granted March 15, 1932, on an ap.- plication led in the name of Fred N. La Chapelle, to measure the thickness of the bottom of a shoe on a last by utilizing the awl of a fastening inserting machine, the awl coming to rest when it strikes an impenetrable member back of the shoe bottom, such as the metal heel or bottom plate on the last. In addition to utilizing the awl to measure the thickness of the shoe bottom, the prior patent also teaches the feasibility of utilizing the work penetrating movement of the awl to vary the lengths of the fastenings in accordance with the measured thickness of the shoe bottom at the points where the fastenings are to be inserted.

It will be seen from the foregoing, however, that since the thickness of the shoe bottom is measured by the work penetrating movement oi' the awl, it is necessary in order to insure an accurate measurement of the shoe bottom, that the awl be maintained in the position in which it came to rest upon striking the metal plate on the last bottom. In other words, in order to secure an accurate measurement of the thickness of the shoe bottom, the awl should not move heightwise relatively to the fastening inserting instrumentalities after it has struck the last bottom even though the last itself does move heightwise as, for example, where the last is depressed or lowered during the feeding of the shoe to relieve pressure on the shoe and thereby facilitate the feeding operation.

It is an object of the present invention to provide improved means applicable, for example, to

machines of the type used for heel seat nailing or pegging, by which the measurement of the thickness of a work piece by the awl is rendered positive and accurate notwithstanding any subsequent movement of the work piece relatively to the awl or to the fastening inserting instrumentalities of the machine.

To the attainment of this object and in accordance with a feature of the invention, there is provided in a machine of the type referred to improved means arranged to maintain the awl positively against further movement in the direction of its work penetrating movement after it has come to rest against an excessive resistance, such as the metal plate on the bottom ci a last, even though the excessive resistance is later removed as, for example, when the last or work support is lowered relatively to the fastening inserting instrumentalities to relieve pressure on the shoe during its feeding movement. As illustrated herein, the awl is reciprocated by means which includes a stiff compression spring strong enough to cause the awl to penetrate the work piece but arranged to yield when the awl meets an excessive resistance, such as the metal plate on the last bottom, thereby permitting the awl to come to rest and thus measure the thickness of the shoe bottom by its work penetrating movement. The awl is then maintained positively against any further movement in the direction of its work penetrating movement under the action of its reciprocating means by further means constructed and arranged to prevent the compression spring from expanding when the resistance is removed from the awl. The lastnamed means, as herein illustrated, comprises a pivoted member having an inclined or convex surface thereon movable into engagement with a roll as the spring yields and serving to hold the spring in its yielded or compressed condition and preventing it from expanding and acting upon the awl to cause further movement thereof when the resistance against the awl is removed. This last-named means is also arranged to move the convex surface out of engagement with the roll when the awl is returned to its inoperative position.

While the invention is illustrated herein as embodied in a fastening inserting machine adapted to drive fiber fastenings or pegs into the bottom portions of shoes, for example, in heel seat nailing or pegging, it should be understood vthat the invention is not limited in its utility to such use or embodiment and, accordingly, the construction disclosed should be regarded as merely one example of the forms in which my invention may be embodied.

With the above and other objects and features in view, the invention will now be described with reference to the accompanying drawing and will thereafter be pointed out in the claims.

In the drawing,

Fig. 1 is a side elevation of the forward portion of the head of a fastening inserting machine embodying the present invention;

Fig. 2 is a view similar to Fig. 1 with the mechanism in a different position;

Fig. 3 is a front elevation of the h'ead of the machine; and

Fig. 4 is an enlarged detail view illustrating the position of the awl relatively to a work piece during feeding movement of the work piece.

The illustrated machine is of the general type disclosed in Letters Patent of the United States No. 1,030,775, granted June 25, 1912, on an application filed in the name of George Goddu, the machine being organized, however, to insert ber pegs instead of loose nails, as disclosed in the La Chapelle Patent No. 1,849,253 above referred to, the pegs being severed from a strip of fiber fastening material such as paper twine. The machine may be advantageously equipped with a work support of the character disclosed in Letters Patent of the United States No. 1,587,848, granted June 8, 1926, on an application filed in the name of F. L. MacKenzie, the pressure relieving mechanism being modified, if desired, as shown in United States Letters Patent No'. 1,686,- 808, granted October 9, 1928, on an application filed in the names of George Goddu and F. L. MacKenzie. Reference may be had to the patents mentioned for a full disclosure of such parts of the machine as it is unnecessary to illustrate herein.

As disclosed in the La Chapelle Patent No. 1,849,253, the machine is provided with a column I Il carrying a head I2 on which are mounted the fastening inserting instrumentalities of the machine. The column I also carries a work support or jack terminating in a last pin I 4 (Fig. 1) and arranged to support a work piece such as a shoe I6 mounted upon a last I8 with its sole 20 in engagement with a presser plate or abutment 22 carried by the head of th'e machine. The shoe may be positioned relatively to the fastening inserting mechanism by a gage 24 of any suitable form also carried by the head of the machine.

Mounted in bearings in the head of the machine is a cam shaft 30 carrying a cam member 32 provided with a series of cam grooves and surfaces arranged to operate the moving parts of the machine. As shown in the La Chapelle patent, the cam shaft 30 may be driven from any suitable source of power by a pulley (not shown) arranged to be thrown into and out of operative engagement with the cam shaft by clutch mechanism which is provided with a brake, this mechanism preferably being actuated by a treadle.

The machine is also provided with a driver bar 34 (Fig. 3) mounted for reciprocating movement in vertical ways carried by the head of the machine and having clamped to its lower end a driver 36. As disclosed in the La Chapelle patent, the driver bar 34 is reciprocated through a rack and gear segment arrangement (not shown) by a bell crank lever 38 (Fig. 1) fulcrumed at 40 to the head of the machine, the bell crank lever having a depending arm which carries a roll positioned in a cam track 42 formed in the cam member 32.

An awl bar carrier 44 (Fig. 3) is mounted for horizontal sliding movement at the front of the machine, and mounted for vertical sliding movement in ways formed in the awl bar carrier is an awl bar 46 having secured to its lower end an awl 48. The awl bar 46 is provided on its rear surface with a rack 59 which meshes with a gear segment 52 formed on the forward end of a lever 54 fulcrumed on a shaft 56 mounted in the head of the machine, the lever 54 being provided with a pair of rearwardly extending arms 58 and 60. The awl bar carrier 44 is reciprocated transversely of the machine by a lever 62 fulcrumed to the head of the machine at 64 and carrying a roll 66 positioned in a cam groove formed in the rear surface of a cam disk 68 secured to the forward end of the cam shaft 30. The rear arm 60 of the lever 54 is adjustably and yieldingly connected by mechanism to be presently described to a bell crank lever 'I0 fulcrumed on a pin 'II and carrying a cam roll 'I2 positioned in a cam track I4 formed in the cam member 32. The awl 48 serves both to form fastening receiving holes in the work piece presented thereto and to feed the work piece toward and past the driver 36, the action of the awl constituting a four-motion feed.

As disclosed in the La Chapelle patent referred to, the arrangement of the mechanism for reciprocating the awl 43 to cause it to penetrate a work piece such as the bottom of the shoe I6 and form fastening receiving holes therein is such that, when the awl meets an excessive resistance such as the metal plate T6 (Figs. 2 and 4) on the bottom of the last I8, the reciprocating means yields and permits the awl to come to rest bearing against the last bottom, thereby causing the awl to measure the thickness of the work piece, for example, the bottom of the shoe I6. Moreover, further mechanism is provided in the machine for feeding a length of ber fastening material 'I8 (Fig. 3) carried by a reel (not shown) mounted on the head of the machine, the length of this peg being controlled by the work penetrating movement of the awl, that is, by the distance which the awl travels in penetrating the shoe bottom before being brought to rest by striking the metal plate I6 on the last bottom.

The strip of ber fastening material 18 is engaged by afeed dog (Fig. 3) and by a spring pressedholding dog 82 which prevents retrograde movement of the fastening material as it is fed into a passageway 84 in line with a forwardly and rearwardly reciprocating throat member 86 which severs the peg from the strip of fastening material during its forward movement, the length of this peg, as pointed out above, being determined by the work penetrating movement of the awl before it is brought to rest by striking the metal plate 'I6 on the last bottom. As already explained, the awl 48 operates to feed the work piece as well as to form fastening receiving holes therein and, as fully disclosed in Letters Patent No. 1,686,808, above referred to, connections are provided between the mechanisms described and the work support which are effective to transmit pressure relieving movement to the work support by depressing or lowering it and the last pin I4 relatively to the abutment 22 and the fastening inserting instrumentalities during the feeding movement, thereby facilitating the feeding of the work piece.

The mechanism which permits the awl to yield when it meets an excessive resistance such as the metal plate on the last bottom, is disclosed in the La Chapelle Patent No. 1,849,253 and comprises the yielding connection referred to above between the rear arm 60 of the lever 54 and the bell crank lever 10, this connection including a bodily movable spring 90 stiff enough to transmit sufcient power to the awl 48 to drive it through the material of a shoe bottom without any yielding action, but yielding sufficiently when the awl strikes the metal plate 16 to permit the awl to come to rest bearing against the last bottom while the bell crank lever completes the rocking movement produced by the cam track 14.

The spring 90 surrounds a sleeve 92 pivoted at its lower end by a pin 94 to the rear arm 60 of the lever 54 and carrying at its upper portion a nut 96 which serves as an adjustable abutment for the upper end of the spring. The lower end of the spring 90 abuts against a collar 98 slidingly mounted on the sleeve 92 and carried at the lower ends of a pair of parallel bars |00 pivotally connected at their upper ends by a stud |02 to a forwardly extending arm |04 of the bell crank lever 10, this arm, as best shown in Figs. 1 and 2, being provided with a curved slot |06 so that the stud |02 may be adjusted along the arm |04 to vary the reciprocating movement of Cil the awl that would be produced by the full stroke of the bell crank lever 10.

It will be clear from the foregoing that the awl 48 is moved downwardly by its reciprocating mechanism until the awl strikes the metal plate 16 on the last bottom at which time the spring 90 yields to permit the awl to come to rest bearing agains the plate 16 while the bell crank lever 10 completes its operative movement. Fig. 1 shows the partsl when the awl is retracted while Fig. 2 shows them after the awl has penetrated the bottom of the shoe |6 and has struck the metal plate 16 and come to rest, the spring 90 having then yielded while the lever 10 completed its operative movement.

It will be evident from Fig. 2 that, when the awl 48 strikes the last bottom and comes to rest, the collar 98 and parallel bars |00 will be moved upwardly under continued rocking movement of the bell crank lever 10, thereby compressing the spring 90 between the collar 98 and the upper abutment 96. Accordingly, the collar 98 will separate from the rear arm 60 and move upwardly to leave an opening or space |08 (Fig. 2) between the collar 98 and the arm 60 which would normally be maintained only while the awl remained in engagement with the last bottom to hold the spring 90 compressed. In other words, if the resistance were removed from the awl as, for example, by the lowering of the last to permit feeding of the work piece, the spring 90 would immediately expand and cause the awl to follow the last downwardly. The spring would expand to move the sleeve 92 upwardly together with the arm 60 until an annular abutment or shoulder |05 formed on the lower end of the sleeve 92 came against the collar 98. If this should happen the length of the fiber peg to be cut for insertion into the fastening receiving hole just formed by the awl would be too long becausey as stated above, the reciprocatory movement of the awl determines the length of the fastening or peg. Accordingly, in order to insure that the fastening will be exactly the right length, it is necessary to maintain the awl 48 positively against any further movement in the direction of its work penetrating movement after it has struck the metal plate 16 on the last bottom and measured the thickness of the shoe bottom, notwithstanding any subsequent heightwise movement of the work support or last relatively to the fastening inserting instrumentalities of the machine.

To this end the lower end of the sleeve 92 is provided with a rearwardly extending arm ||0 carrying a roll |2. The right-hand parallel bar |00, as viewed in Figs. l and 2, is provided with a laterally extending lug ||4 to which is pivoted on a pin ||6 a downwardly extending lever H8, the lower end of this lever being provided with a convex cam surface |20 arranged to engage the roll ||2 on the arm ||0. The lever ||8 also has a short arm |22 near its upper end which carries a roll |24. This lever ||8 is further provided at its lower portion with a rearwardly extending projection |26 to the outer end of which is secured by a pin |28 a tension spring |30. The spring |30 extends toward the front of the machine and is fastened at its forward end to a hook |32 secured in the hub of the lever 54. The spring |30 ltends constantly to urge the lever |I8 forwardly about its pivot I I6 to move the convex cam surface |20 further into engagement with the roll |2 carried by the arm I|0 on the sleeve 92, the cam surface |20 being eccentric relatively to the pivot I6 and so inclined that the distance between the roll |`|2 and the pivot |I6 of the lever ||8 becomes greater as the lever swings forwardly.

Accordingly, when the awl 48 strikes the excessive resistance of the metal plate 16 on the bottom of the last I8, and the spring yields or compresses to permit the awl to come to rest f while the bell crank lever 10 continues its operative movement, the space |08 created between the collar 98 and the shoulder |05 on the sleeve 92 is immediately taken up by the cam surface |20 being moved further forwardly over the roll H2 by the spring |30. This action, therefore, positively maintains whatever space is created between the sliding collar 98 and the shoulder |05 on the sleeve 92 by preventing the spring 90 from expanding and moving the lever 60 and sleeve 92 upwardly when the excessive resistance is removed from the awl 48. Consequently, the awl which is connected to the arm 60 by the gear teeth on the lever 54 'cannot move downwardly with the shoe when the last is lowered to facilitate the feeding movement of the shoe.

After the feeding movement has taken place, it is necessary to remove the lever I8 from operative engagement with the roll l2 to permit the awl to return to its inoperative position or, in other words, to return the control of the awl to its reciprocating mechanism with this mechanism in its normal or inoperative position. The lower arm of the bell crank lever 10 is provided with a rearwardly extending projection |34 having a convex upper surface which is arranged to engage the roll |24 on the short arm |22 of the lever ||8 when the lever 10 is being rocked in a counterclockwise direction to return it to its inoperative position. Engagement of the projection |34 with the roll |24 swings the lever 8 rearwardly about the pivot ||6 until the lever assumes the position shown in Fig. 1. Although this return movement of the parts takes place against the tension of the spring |30 and also against the force of the compression spring 90, it is accomplished without any undue strain on the moving parts because of the rolling engagement between the roll ||2 and the convex surface |20 which greatly reduces friction. The projection |34 serves thereafter to maintain the lever l l 8 in its rearward position by engagement with the roll |24 until the bell crank lever 10 is again operated to reciprocate the awl downwardly to form another fastening receiving hole in the shoe bottom.

Fig. 4 illustrates, on an enlarged scale, the relative positions of the awl, shoe, and abutment 22 when the shoe has been lowered for the feeding movement and shows the awl being maintained in vthe heightwise position in which it came to rest by engaging the metal plate 'I6 on the last bottom although the last and shoe have been lowered relatively to the abutment 22 to facilitate feeding the shoe.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate a work piece and to form fastening receiving holes in the work piece, said means being arranged to yield when the awl meets an excessive resistance, thereby permitting the awl to come to rest, and means additional to said reciprocating means constructed and arranged to maintain the awl positively against further movement in a work penetrating direction under the action of its reciprocating means when the excessive resistance is removed.

2. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate a work piece mounted on a support and to form fastening receiving holes in the work piece, said means being arranged to yield when the awl strikes the support, thereby permitting the awl to come to rest bearing against said support, and means constructed and arranged positively to prevent the awl from continuing its movement in a work penetrating direction under the action of its reciprocating means after the awl has come said support.

3. A fastening inserting machine having, in.

combination, an awl, means for reciprocating the awl heightwise to cause it to penetrate a work piece mounted on a support, thereby forming fastening receiving holes in the work piece, said means having a predetermined movement but being arranged to yield when the awl strikes the support, thereby permitting the awl to come to rest pressed against the support, means for feeding the work piece with the support depressed to relieve pressure on the work piece, and means additional to the reciprocating means and operating independently thereof for maintaining the awl positively in the heightwise position in which it came to rest when the support is depressed to permit feeding of the work piece.

4. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means including a spring arranged to yield when the awl strikes the bottom of the last to permit the awl to come to rest bearing against the last bottom, thereby causing the awl to measure the thickness of the shoe bottom, means for lowering the last and shoe to facilitate feeding the shoe, and means constructed and arranged to maintain said spring positively in its yielded condition and thereby to prevent the reciprocating means from causing further movement of the awl in the direction of its work penetrating movement when the last is lowered.

to rest against 5. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means comprising a lever having a predetermined operative movement, an awl actuating lever, and connections between said levers arranged to yield when the awl strikes the bottom of the last to permit the awl to come to rest pressed against the last bottom while said lever completes its operative movement, thereby causing the awl to measure the thickness of the shoe bottom, means for inserting in said holes fastenings measured to correspond in length to the measured thickness of the shoe bottom, means for lowering the last and shoe to relieve the pressure on the shoe as it is fed past the fastening inserting means, and means constructed and arranged to maintain said connections positively in their yielded positions to prevent movement of the awl with the last away from said fastening inserting means, thereby insuring accurate measurement of the thickness of the shoe bottom by the awl.

6. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means including a member having a predetermined reciprocating movement and a spring arranged to yield when the awl strikes the bottom of the last to permit the awlfto come to rest bearing against the last bottom while said member completes its reciprocating movement, thereby causing the awl to measure the thickness of the shoe bottom during its work penetrating movement, means controlled by the depth to which the awl penetrates the shoe bottom for severing fastenings of a length corresponding to the thickness of the shoe bottom measured by the awl when it came to rest, means for lowering the last relatively to the awl to relieve pressure on the shoe during the feeding of the shoe, and means constructed and arranged to hold the spring positively in its yielded position to prevent the awl from being lowered with the last in a Work penetrating direction by said reciprocating means during the feeding movement, thereby insuring that the measurement of the thickness of the shoe bottom by the awl will be correct.

'7. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate a work piece to form fastening receiving holes therein, said means including a spring arranged to yield when the awl meets an excessive resistance, thereby permitting the awl to come to rest, means for lowering the work piece to facilitate the feeding operation, and means constructed and arranged to maintain the awl positively against further movement in the direction of its work penetrating movement under the action of said spring when the work piece is lowered, said means comprising mechanism arranged to maintain the spring in its yielded condition thereby preventing said spring from acting upon the awl.

8. A fastening inserting machine having, in combination, fastening inserting means, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means including a spring stiff enough to cause the awl to penetrate the shoe bottom but arranged to yield when the awl strikes the bottom of the last, thereby permitting the awl to come to rest bearing against the last bottom, means for feeding the shoe intermittently past the fastening inserting means to receive successive fastenings, means for lowering the shoe relatively to the fastening inserting means to relieve pressure on the shoe during the feeding, and means constructed and arranged to maintain the awl positively against downward movement with the shoe under the action of said spring when the shoe is lowered for the feeding movement, said means being also arranged to release its control of the awl during the intervals between feeding movements.

9. A fastening inserting machine having, in combination, fastening inserting means, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means including a stiff spring substantially unyielding during the work penetrating movement of the awl but arranged to yield when the awl strikes the last bottom, thereby permitting the awl to come to rest bearing against the last bottom, means for feeding the shoe intermittently past the fastening inserting means for the insertion of successive fastenings, means for lowering the last relatively to the fastening inserting means to relieve pressure on the shoe during the feeding, means for preventing the awl from moving downwardly with the last when the last is lowered for the feeding movement, said means including a member arranged to move with the awl during its work penetrating movement, a pivoted member movable with the spring during the yielding action of said spring, and means for moving said members into operative engagement with each other during the feeding of the shoe to prevent the spring from expanding and acting upon the awl.

lo. A fastening inserting machine having, in combination, fastening inserting means, an awl, means for reciprocating the awl heightwise to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means including a compression spring bodily movable to transmit work penetrating movement to the awl but being arranged to yield when the awl meets the excessive resistance of the last bottom, thereby permittingr the awl to come to rest bearing against the last bottom, means for intermittently feeding the shoe past the fastening inserting means for the insertion of successive fastenings, means for lowering the shoe relativelly to the fastening inserting means during each feeding movement, and means for positively maintaining the awl in the heightwise position in which it was stopped by the last bottom during each lowering of the shoe, said means including a member arranged to move with the awl during its work penetrating movement, an upper surface on said member, a pivoted lever arranged to move with the spring during the yielding action of said spring, a surface on said lever eccentric relatively to its pivot, and means for swinging said lever to move the eccentric surface thereon into and out of engagement with the upper surface on said member in timed relation with the operation of said feeding means, thereby maintaining the spring compressed during each feeding movement of the shoe.

l1. A'fastening inserting machine having, in combination, an awl, means including a spring for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said spring being substantially unyielding during the work penetrating movement of the awl but being arranged to yield when the awl strikes the bottom of the last thus permitting the awl to come to rest bearing against the last bottom, an abutment for engaging the shoe bottom, means for feeding the shoe intermittently, means for lowering the last relatively to said abutment to relieve pressure on the shoe during the feeding movement, means for maintaining the awl positively in the heightwise position in which it carne to rest against the last bottom each time the last is lowered for the feeding movement, said means including a member movable with the awl during its work penetrating movement, a pivoted lever movable with the spring during the yielding action of said spring, resilient means for moving said member and said pivoted lever into engagement with each other during each feeding movement, thereby preventing the spring from expanding and acting upon the awl, and positively operated means for moving said member and lever out of engagement with each other during the intervals between feeding movements.

l2. A fastening inserting machine having, in combination, an awl, means for reciprocating the awl to cause it to penetrate the bottom of a shoe mounted on a last to form fastening receiving holes in the shoe bottom, said means comprising a rocking lever, means for rocking said lever, a second rocking lever arranged by its rocking movement to reciprocate the awl, means including a spring connecting the two levers and arranged to transmit rocking movement from the first-named lever to the second lever but to yield to permit the first-named lever to continue its rocking movement when the second lever is no longer able to rock by reason of the awl having struck an impenetrable member on the bottom of the last, thereby permitting the awl to come to rest bearing against the last bottom, means for lowering the last relatively to the awl, and means for maintaining the awl positively against further movement in the direction of its work penetrating movement when the last is lowered relatively to the awl, said means comprising a member connected to said second lever and movable therewith, a surface on said member, a pivoted lever movable with the spring whenever the spring yields, and spring means foi` urging said pivoted lever into engagement with said surface when the spring yields, thereby preventing the spring from expanding and acting upon the awl when the last is lowered.

GUY R. COYNE. 

